There are known microorganisms capable of synthesizing hydrocarbons such as alkane. It is expected that the development of recombinant microorganisms having excellent hydrocarbon synthesis capacity, hydrocarbon synthesis systems using the recombinant microorganisms, and the like would be possible through the isolation/separation of genes involved in hydrocarbon synthesis from such microorganisms having hydrocarbon production capacity. For example, Patent Literature 1 (WO2006/109558) discloses a method for obtaining a hydrocarbon from a culture product, which comprises culturing novel microalgae having hydrocarbon synthesis capacity, such as Pseudochoricystis ellipsoidea, or microalgae belonging to the genus Pseudochoricystis or Choricystis which have hydrocarbon production capacity.
In addition, Patent Literature 2 (JP Patent Publication (Kokai) No. 2010-528627 A) discloses a recombinant yeast obtained by incorporating a gene capable of converting aldehyde into alkane into yeast or the like and a method for producing alkane using the recombinant yeast. Patent Literature 3 (JP Patent Publication (Kohyo) No. 2011-520455 A) discloses an alkane synthase gene and an aldehyde synthase gene from Synechococcus elongatus and a method for producing alkane and aldehyde using such genes. Patent Literature 4 (JP Patent Publication (Kokai) No. 9-322780 (1997) A) discloses a gene encoding a protein involved in the activity of Arabidopsis thaliana-derived fatty aldehyde decarbonylase and a transformed plant showing an altered epicuticular wax composition obtained using the gene.
Further, Non-Patent Literature 1 (Process Biochemistry, 41, (2006), pp. 1001-1014) discloses the hydrocarbon synthesis pathway in a microorganism. Non-Patent Literature 2 (Appl. Microbiol. Biotechnol., (2005), 66: pp. 486-496) discloses biosynthesis of hydrocarbons in Botryococcus braunii, which is an alga, as in the case of Patent Literature 1. Patent Literature 3 (Proc. Natl. Acad. Sci., (1994), Vol. 91, pp. 10000-10004) discloses a fly-derived cytochrome P450 gene capable of converting aldehyde into a hydrocarbon ((Z)-9-tricosene).
However, applied use of the microorganism disclosed in Non-Patent Literature 1 and the fly-derived gene disclosed in Non-Patent Literature 3 at practical level cannot be expected because of low alkane production. In addition, in the cases of the algae disclosed in Non-Patent Literature 2 and Patent Literature 1, the alkane production reaction rate is low, resulting in intracellular accumulation of alkane. For such reasons, low-cost synthesis of alkane cannot be achieved even with the use of the algae disclosed in Non-Patent Literature 2 and Patent Literature 1 because alkane production is time-consuming and a step of purifying alkane from cells must be added. This is problematic. Further, there are no practical examples of successful alkane synthesis even by producing a recombinant with the gene disclosed in Patent Literature 4; such synthesis is not practical because an additional factor (i.e., an unknown gene) is necessary. Furthermore, even if a plant-derived gene is used for a microorganism, the gene might not sufficiently function therein. This is also problematic. In addition, the use of the cyanobacteria-derived alkane synthase gene disclosed in Patent Literature 3 would result in low productivity of alkane synthesis. The use of such gene is almost impractical.